Recently, decoration on a surface of a housing of a mobile phone or a portable game console by attaching to the surface a decoration sheet on which a pattern or the like is printed has been carried out. For attaching such a decoration sheet, a pressure-sensitive adhesive sheet such as a double-sided pressure-sensitive adhesive sheet has been generally used.
In recent years, a liquid crystal display (LCD) is often provided on housings of mobile phones, and a pressure-sensitive adhesive sheet to be used for such housings is required to have a light-shielding property from the viewpoints of prevention of stray light from the LCD to thereby improve surface decorativity.
As the pressure-sensitive adhesive sheet having a light-shielding property which satisfies the above-described requirements, pressure-sensitive adhesive sheets (including tape) having a black light-shielding layer have been known (see Patent References 1 to 13, for example). However, along with thickness reduction of mobile phones, the decoration sheet and the pressure-sensitive adhesive sheet have been thinned. Consequently, in the case of using such pressure-sensitive adhesive sheets having the light-shielding layer, a problem of deteriorations in designability and decorativity has occurred due to a phenomenon that the black light-shielding layer is seen through a surface of the decorative sheet.
Patent Reference 1: JP-A-2004-59723
Patent Reference 2: JP-A-2005-213282
Patent Reference 3: JP-A-2007-9137
Patent Reference 4: JP-A-2002-235053
Patent Reference 5: JP-A-2002-350612
Patent Reference 6: JP-A-2004-161955
Patent Reference 7: JP-A-2004-184443
Patent Reference 8: JP-A-2004-231736
Patent Reference 9: JP-A-2004-156015
Patent Reference 10: JP-A-2004-244499
Patent Reference 11: JP-A-2002-249741
Patent Reference 12: JP-A-2004-053759
Patent Reference 13: JP-A-2002-023663